/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: AttributeSet.java,v 1.5 2005/09/28 13:48:04 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.compiler;

import java.util.Enumeration;
import java.util.Vector;

import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.INVOKESPECIAL;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.AttributeSetMethodGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Util;
import com.sun.org.apache.xml.internal.utils.XML11Char;

/**
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 * @author Morten Jorgensen
 */
final class AttributeSet extends TopLevelElement {

  // This prefix is used for the method name of attribute set methods
  private static final String AttributeSetPrefix = "$as$";

  // Element contents
  private QName _name;
  private UseAttributeSets _useSets;
  private AttributeSet _mergeSet;
  private String _method;
  private boolean _ignore = false;

  /**
   * Returns the QName of this attribute set
   */
  public QName getName() {
    return _name;
  }

  /**
   * Returns the method name of this attribute set. This method name is
   * generated by the compiler (XSLTC)
   */
  public String getMethodName() {
    return _method;
  }

  /**
   * Call this method to prevent a method for being compiled for this set.
   * This is used in case several <xsl:attribute-set...> elements constitute
   * a single set (with one name). The last element will merge itself with
   * any previous set(s) with the same name and disable the other set(s).
   */
  public void ignore() {
    _ignore = true;
  }

  /**
   * Parse the contents of this attribute set. Recognised attributes are
   * "name" (required) and "use-attribute-sets" (optional).
   */
  public void parseContents(Parser parser) {

    // Get this attribute set's name
    final String name = getAttribute("name");

    if (!XML11Char.isXML11ValidQName(name)) {
      ErrorMsg err = new ErrorMsg(ErrorMsg.INVALID_QNAME_ERR, name, this);
      parser.reportError(Constants.ERROR, err);
    }
    _name = parser.getQNameIgnoreDefaultNs(name);
    if ((_name == null) || (_name.equals(EMPTYSTRING))) {
      ErrorMsg msg = new ErrorMsg(ErrorMsg.UNNAMED_ATTRIBSET_ERR, this);
      parser.reportError(Constants.ERROR, msg);
    }

    // Get any included attribute sets (similar to inheritance...)
    final String useSets = getAttribute("use-attribute-sets");
    if (useSets.length() > 0) {
      if (!Util.isValidQNames(useSets)) {
        ErrorMsg err = new ErrorMsg(ErrorMsg.INVALID_QNAME_ERR, useSets, this);
        parser.reportError(Constants.ERROR, err);
      }
      _useSets = new UseAttributeSets(useSets, parser);
    }

    // Parse the contents of this node. All child elements must be
    // <xsl:attribute> elements. Other elements cause an error.
    final Vector contents = getContents();
    final int count = contents.size();
    for (int i = 0; i < count; i++) {
      SyntaxTreeNode child = (SyntaxTreeNode) contents.elementAt(i);
      if (child instanceof XslAttribute) {
        parser.getSymbolTable().setCurrentNode(child);
        child.parseContents(parser);
      } else if (child instanceof Text) {
        // ignore
      } else {
        ErrorMsg msg = new ErrorMsg(ErrorMsg.ILLEGAL_CHILD_ERR, this);
        parser.reportError(Constants.ERROR, msg);
      }
    }

    // Point the symbol table back at us...
    parser.getSymbolTable().setCurrentNode(this);
  }

  /**
   * Type check the contents of this element
   */
  public Type typeCheck(SymbolTable stable) throws TypeCheckError {

    if (_ignore) {
      return (Type.Void);
    }

    // _mergeSet Point to any previous definition of this attribute set
    _mergeSet = stable.addAttributeSet(this);

    _method = AttributeSetPrefix + getXSLTC().nextAttributeSetSerial();

    if (_useSets != null) {
      _useSets.typeCheck(stable);
    }
    typeCheckContents(stable);
    return Type.Void;
  }

  /**
   * Compile a method that outputs the attributes in this set
   */
  public void translate(ClassGenerator classGen, MethodGenerator methodGen) {

    if (_ignore) {
      return;
    }

    // Create a new method generator for an attribute set method
    methodGen = new AttributeSetMethodGenerator(_method, classGen);

    // Generate a reference to previous attribute-set definitions with the
    // same name first.  Those later in the stylesheet take precedence.
    if (_mergeSet != null) {
      final ConstantPoolGen cpg = classGen.getConstantPool();
      final InstructionList il = methodGen.getInstructionList();
      final String methodName = _mergeSet.getMethodName();

      il.append(classGen.loadTranslet());
      il.append(methodGen.loadDOM());
      il.append(methodGen.loadIterator());
      il.append(methodGen.loadHandler());
      il.append(methodGen.loadCurrentNode());
      final int method = cpg.addMethodref(classGen.getClassName(),
          methodName, ATTR_SET_SIG);
      il.append(new INVOKESPECIAL(method));
    }

    // Translate other used attribute sets first, as local attributes
    // take precedence (last attributes overrides first)
    if (_useSets != null) {
      _useSets.translate(classGen, methodGen);
    }

    // Translate all local attributes
    final Enumeration attributes = elements();
    while (attributes.hasMoreElements()) {
      SyntaxTreeNode element = (SyntaxTreeNode) attributes.nextElement();
      if (element instanceof XslAttribute) {
        final XslAttribute attribute = (XslAttribute) element;
        attribute.translate(classGen, methodGen);
      }
    }
    final InstructionList il = methodGen.getInstructionList();
    il.append(RETURN);

    classGen.addMethod(methodGen);
  }

  public String toString() {
    StringBuffer buf = new StringBuffer("attribute-set: ");
    // Translate all local attributes
    final Enumeration attributes = elements();
    while (attributes.hasMoreElements()) {
      final XslAttribute attribute =
          (XslAttribute) attributes.nextElement();
      buf.append(attribute);
    }
    return (buf.toString());
  }
}
